MONOCOTYLEDONS. CYPERACE.'E. Sdrpus. 



2. SCHCENUS. 



Scales imbricating the spike on all sides, the exterior ones smaller, 

 without flowers. Achenium naked or with a few bristles at 

 its base. 



* Culms leafy. 



1. Sch. allus, culm triangular, leaves linear-setaceous, flowers 

 terminal subcorymbose as long as the involucrum. p. 16. Bogs. 



'** Culms naked. 



2. Sch. nigricans, culm rounded, spikelets of flowers collected 

 into an ovate cluster, involucrum of two leaves, the exterior 

 one longer than the flowers, p. 16. Bogs. 



3. Sch. compressus, culm roundish, spike distichous shorter 

 than the monophyllous involucrum, spikelets many-flowered, 

 leaves plane, p. 16. Bogs, rare. 



4. Sch. rufus, culm rounded, spike distichous longer than the 

 involucrum, spikelets few-flowered, leaves setaceous channelled, 

 p. 17. Wet moors. 



3. SCIRPUS. 



Scales imbricating the spike on all sides, one or two of the outer 

 ones occasionally without flowers. Achenhttn naked, or with 

 bristles at its base. 



* Spike solitary. 

 f Culms simple. 



1. Sc. ccespitosus, culm rounded, sheath terminating in the ru- 

 diments of leaves, two outer scales as long as the spike invo- 

 lucrate, stigmas 3. p. 17. Moors. 



2. Sc. pauciflorus, culm rounded, sheaths leafless, spike ovate 

 naked, scales obtuse nearly equal, two outer ones the largest 

 but shorter than the spike, stigmas 3. p. 17. Mountains. 



3. Sc. palustrJSj culm rounded, sheaths at the base leafless, 

 spike oblongo-ovate naked, scales nearly equal in size, stigmas 

 2. p. 18. Marshes. 



4. Sc. acicularis, culm compressed grooved, sheaths leafless, 

 spike ovate acute naked (no involucrum), scales acuminate, 

 stigmas 3, fruit without bristles, p. 18. Marshes. 



ff Culms branched. 



5. Sc. Jlmtans 9 culm rounded leafy flaccid, spikes ovate naked 

 (no involucrum), scales rather obtuse, stigmas 2, fruit desti- 

 tute of bristles, p. 1 8. Ditches. 



** Spikelets many. 

 f Culms rounded. 



6. Sc. lacustris, upper sheaths leafy, cyme terminal twice com- 

 pound, involucrum 2-leaved. p. IS. Sides of lakes. 



1 . Sc. setaceus, culms setaceous rounded or very slightly com- 



